21534968755 has 4 divisors (see below), whose sum is σ = 25841962512. Its totient is φ = 17227975000.

The previous prime is 21534968743. The next prime is 21534968759. The reversal of 21534968755 is 55786943512.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21534968755 - 2⁵ = 21534968723 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21534968696 and 21534968705.

It is not an unprimeable number, because it can be changed into a prime (21534968759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2153496871 + ... + 2153496880.

It is an arithmetic number, because the mean of its divisors is an integer number (6460490628).

Almost surely, 2^21534968755 is an apocalyptic number.

21534968755 is a deficient number, since it is larger than the sum of its proper divisors (4306993757).

21534968755 is an equidigital number, since it uses as much as digits as its factorization.

21534968755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4306993756.

The product of its digits is 9072000, while the sum is 55.

The spelling of 21534968755 in words is "twenty-one billion, five hundred thirty-four million, nine hundred sixty-eight thousand, seven hundred fifty-five".